Boom extension



May 3, 1966 J, ELLERBROEK ET AL 3,249,244

BOOM EXTENSION 2 Sheets-Sheet 1 Filed Sept. 17. 1964 Tia.

INVENTOBS ELTON B. LONG J'oN JT ELLERBROEK Uzlson, Stflie & Crag Armenia5 y 1966 J. J. ELLERBROEK ET AL 3,249,244

BOOM EXTENSION Filed Sept. 17, 1964 2 Sheets-Sheet 2 INVENTORS ELTON 5.LONG BY Jo- J. ELLERBROEK 0115011., Settle & Cray flrroRNEYJ UnitedStates Patent ration of Wisconsin Filed Sept. 17, 1964, Ser. No. 397,1356 Claims. (CL 214-138) The present invention relates to tractor mounteddigging apparatus and more specifically to a system, including methodand apparatus, for inexpensively modifying the existing booms on tractormounted backhoes and the like to increase the trenching depth capabilitythereof without significant alteration in the existing backhoe structureor in impairment of the structural integrity thereof.

In the recent past, the building codes of many cities and otherjurisdictions have undergone ignificant changes and now requireplacement of water, sewage and like pipes at deeper locations beneaththe ground surface. Some existing excavation equipment of the backhoetype lack the capability to trench to the new depths required.Consequently it has become advisable to modify this backhoe equipment soas to increase the depth of trenching capability sufficient to satisfythe new building code requirements.

One way of making such modifications to existing backhoe equipment is tore-tool at the factory and manufacture new component parts of extendedlength which may be used to replace the smaller existing components onthe backhoe equipment. The cost of such an undertaking is usuallyprohibitive when balanced against the cost to the consumer.Consequently, to be economically feasible, the required increase intrenching capability must be achieved by some type of adaptation of theexisting component parts of the equipment.

In the past, attempts to modify existing components of the existingbackhoe trenching equipment have met with extremely limited commercialsuccess because of extra weight, poor weight distribution, increasedheight of clearance during transportation from one job site to another,and like problems.

The present invention satisfactorily solves the foregoing problems andcomprehends a novel, multi-positionable extension member designed toover-fit a tractor mounted backhoe boom and to pivotally connect to thedipper stick thereof. The extension member of this invention requiresonly limited reworking of the boom. No structural changes to the boomare required. The extension member may be installed upon the boom in arelatively brief period of time, with incurrence of only nominal costs.The extension may be rigidly fastened in any one of several positionsalong the boom and may be rigidly relocated from one position toanother, as desired.

In accord with the foregoing, it is a primary object of the presentinvention to provide an extension member, mountable upon the distal endof a tractor mounted backhoe boom or the like, which may be selectively,rigidly positioned in any one of a plurality of positions along theboom, so that the trenching capability of the boom may be selectivelyextended or decreased.

The extension member of this invention may be embodied to have one ormore of the following features:

(1) Good balance characteristics, i.e., a favorable center of gravitywhen installed in one of its several rigid positions between the backhoeboom and the dipper stick;

(2) Relatively light in weight;

(3) Low height clearance characteristics to accommodate easytransportation from one work site to another and thereby avoidinterference with existing power lines and the like;

(4) Selectively positionable between extended and re- 3,249,244 PatentedMay 3, 1966 ice tracted positions to provide variable maximum depth oftrenching capabilities;

(5) Lending itself to a handy method for installation of the extensionmember, requiring only a small amount of equipment downtime, limitedmanpower and no specialized equipment to physically install or removethe extension;

(6) Relatively low in cost so as not to be economically prohibitive tothe ultimate consumer;

(7) Conveniently installable by non-technical persons, such as thepurchasing consumer;

(8) Repositionable in any one of a plurality of rigid positions alongthe boom by one man, such as the operator of the machine, in arelatively short period of time without any requirement of additionalpower tools and the like; and

(9) Requiring only a minimum of rework to the backhoe boom andnecessitating no major changes to the hydraulic equipment existing onthe boom.

These and other objects and features of the present invention willbecome more fully apparent from the appended claims as the ensuingdetailed description proceeds in conjunction with the accompanyingdrawings in which:

FIGURE 1 is a side elevation illustrating a presently preferredextension member as embodied by this invention in its installed workingposition. The horizontally illustrated backhoe apparatus of FIGURE 1shown in dotted lines illustrates the extension member rigidly locatedin its retracted working position, while the vertical, illustratedbackhoe apparatus shown in solid lines illustrates the extension memberrigidly located in its extended working position;

FIGURE 2 is a side elevation solely of the extension member of FIGURE 1;

FIGURE 3 is a partial cross-section, taken along the lines 33 of FIGURE1, illustrating the slide block assembly carried by the extension memberin its installed position upon the boom;

FIGURE 4 is a rear elevation of the slide block assembly of FIGURE 3;and

FIGURE 5 is a partial side elevation of the backhoe boom of FIGURE 1,showing the limited alterations necessary to adapt it to receive theextension member of FIGURES 2, 3 and 4.

Referring now to the drawings, FIGURE 1 illustrates a presentlypreferred embodiment of the present invention in its installed positionwithin the backhoe apparatus of a tractor mounted backhoe. From FIGURE1, it is to be noted that the extension member maybe selectively positioned in (l) a retracted orientation upon the backhoe boom, as shown bythe dotted-lined, substantially horizontally extending backhoeapparatus, and (2) in an extended position upon the backhoe boom, asillustrated by the solid-lined, substantially vertically extendingbackhoe apparatus of that figure.

It is to be remembered that the extension member, as embodied in FIGURE1, is rigidly fixed in either the retracted or the extended position anddoes not move relative to the backhoe boom during digging or trenchingoperation. When the extension member is in the retracted position, itstrenching pattern is such as is illustrated by the dotted line containedwithin the graph of FIGURE 1. When the backhoe apparatus is in itsfixed, extended position, the digging pattern is as is illustrated bythe solid line contained within the graph of FIGURE 1.

Specifically, backhoe apparatus 10 is mounted upon supports 14 and 16 atthe rear of the tractor 12, which may be a track or rubber-tire tractor.These supports define a vertical axis about which backhoe apparatus 10may pivot by actuation of proper hydraulic controls. Swing linkagesupport 18 is pivotally connected to tractor supports 14 and 16 andprovides a horizontally extending pivot connection 20 about which abackhoe boom 22 may be hydraulically pivoted. This pivot action isresponsive to energizing and deenergizing of boom cylinder assembly 24.

The piston rod of cylinder assembly 24 is pivotally fixed to boom 22toward its distal end through the aperture 23 (see FIGURE and ispivotally anchored upon swing linkage support 18 at anchor 26. Backhoeboom 22 also carries anchor bracket 28 upon which anchor 30 is mounted.Anchor 30 normally carries the proximal end of the dipper stick cylinderassembly 40, i.e., when apparatus has not been modified by installationof the novel extension member of the present invention. Externally,telescopically mounted upon the distal end of boom 22 is shoe extensionmember 32 which is nonrotatably and non-movably held in the selectedposition during trenching. Extension member 32 is pivotably connected atpin connection 34 to the triangular support member 36 of dipper stick38, and anchors the proximal end of the cylinder of the dipper stickcylinder assembly 40 by means of anchor plates 42. Plates 42 are rigidlyheld in the illustrated position with respect to extension member32,,as, for example, by welding.

Dipper stick 38 pivotably anchors bucket cylinder assembly 44 atconnection 46 of triangular support member 36. Cylinder assembly 44 ispivotably connected at its piston rod end to links 48 and 50'. Link 48,in turn, is pivotably attached to the dipper stick 38 and link 50 tobucket mounting bracket 52, which is integrally attached to bucket 54.

Hydraulic apparatus and control of cylinder assemblies 24, 40 and 44 aswell as the hydraulic apparatus of swing linkage support 18 areconventional and form no part of the present invention. Hence, nofurther description of the hydraulics of backhoe apparatus is deemednecessary. The excavation or trenching procedure by use of backhoe 10 isthe same as if extension member 32 were not present, with the exceptionof digging depth'capability. By inspection of FIGURE 1, it is apparentthat the maximum I.E.M.C. (Industrial Equipment Manufacturers Council)digging depth of the illustrated backhoe apparatus is in excess of 14feet, when the extension member is rigidly held in its retractedposition and greater than 16 feet when the extension member is rigidlyheld in its extended position. These digging depths represent animprovement of on the order of one foot and two and one-half feet,respectively, for the retracted andextended positions of extensionmember 32.

The changes required in backhoe apparatus 10 incident to installation ofextension member 32 are extremely nominal and have economic and utilityadvantages not present in any other known prior art apparatus forextending the trenching capability of an existing excavating equipmentof the type described.

To illustrate the precise construction of extension member 32 and toillustrate modifications necessary to boom 22 and its correlation withextension member 32, in both the retracted and extended positions,reference is now made to FIGURES 2. through 5.

FIGURE 2 illustrates extension member 32 isolated from boom member 22and dipper stick 38. Extension member 32 includes open-ended box 60which takes the shape of the shoe, being open at the lefthand end 62 andcapable of being fitted over the distal end of the boom 22. The box 60is closed at its distal end 64 which defines the limit which extensionmember 32 may be retracted upon the boom 22 in the installed position.The box 60 may be formed, for example, from standard rolled steelshapes. As an illustration, a pair of standard rolled steel channelmembers may be fabricated and welded together to form open-ended box 60.

A support anchor pate 42 is mounted on each side of the box member 60 soas to be in transverse alignment with each other, for example, bywelding. Plates 42 are pin connected by means of apertures 66 to anchorthe cylinder end of the dipper cylinder assembly 40 when extensionmember 32 is in its installed working position. Each plate 42 also isprovided with a lower aperture 68 (see FIGURE 3) through which slideblock assembly 70 passes for movable surface support engagement withboom 22, as hereinafter to be explained.

Each slide block assembly 70 (see FIGURE 3) is bolt mounted to plate 42and box 60 by means of bolts 72 and includes bearing plate 74 integrallyconnected, as for example, by Welding to concentric cylindrical pin 76..The pin 76 is j-ournaled within a bushing 77 within a square slide plate78 internal of the box 60 adjacent and in contiguous relation with theboom 22 (see FIG- URES 3 and 4). Each slide block assembly 70, at squareplate 78, is supported by guide plates secured to the sides of the boom22 in a manner and for a purpose which will be subsequently explained.

The box member 60 also contains aligned bossed apertures 80 on itsrespective sides for pin connection with the distal pin fitting of boom22 when the extension 32 is positioned in its extended position, asshown in the vertically oriented embodiment of FIGURE 1.

An end casting 82 is rigidly fastened to the box member 60 at juncture84 as, for example, by Welding. End casting 82 has a hollow recess 86terminating at the end wall 64, and is provided with bossed aperture 88which is pin attached to the distal aperture of boom 22 when extensionmember 32 is installed in its retracted position. End casting 82 alsoprovides a bossed aperture 90' which, in the assembled position, issecured to connection 34 of pivot member 36 of the dipper stick 38.Abutment 92, also part of end casting 82, is used as a limit stop toprevent excessive counter clockwise rotation of pivot member 36, asviewed in FIGURE 1.

In order to adapt boom 22 to accept extension member 32 in over-fittingrelation, guide plates 94 and 96 and stop plates 98 and 100 are fixed toeach side of the boom 22, for example, by Welding. By inspection ofFIGURE 5, it should be noted that guide plates 94 and 96 runsubstantially parallel to distal top surface 102 of the boom 22.

When the extension member 32 is installed upon the boom 22, asillustrated in FIGURE 3, the square side block 78 of each of the twoslide block assemblies 70 is closely interposed intermediate guideplates 94 and 96 between stop plates 98 and 100. Accordingly, when slideblocks 78 are immediately adjacent stop plate 100, extension member 32will be in its retracted position upon boom 22. In this retractedposition, a pin assembly is securely fitted through bossed aperture 88of the extension member 32an-d bossed terminal aperture 104 on thedistal end of the boom 22 (see FIGURE 5) to thereby prevent relativemovement of the extension member and boom with respect to each otherduring trenching operations with backhoe apparatus 10.

When the slide blocks 78 are positioned immediately adjacent theirrespective stop plates 98, extension member 32 is in its extendedposition with respect to boom 22. In the extended position, apinassembly extends through a bossed aperture .80 of extension member 32and bossed aperture 104 on the distal end of the boom 22.

Hence, the two pins 76 are designed to be rotatable within bushing 77 topermit alignment of aperture 80 and aperture 104, .or aperture 90 and104, as the case may be, without binding slide blocks 78 between guideplates 94 and 96.

With reference to FIGURE 1, backhoe apparatus 10, when extension member32 has not been installed thereupon, has the cylinder end of cylinderassembly 40 anchored pivotably in connection 30. In this condition, thepin of connection 34 of pivot member 36 is also fitted through distalend of bossed aperture 104 of the boom 22 (FIGURE 5).

To modify and adapt the backhoe apparatus for reception of extensionmember 32 upon the boom 22, only limited inexpensive steps need beconducted. First, with the possible exception of repositioning of thehydraulic apparatus, such as hydraulic lines and fittings or likeincidental equipment features used in conjunction with backhoe apparatus10, the only structural change required is the welding or like placementof guide plates 94 and 96, and stop plates 98 and 100, upon each side ofthe boom. No additional changes are required.

To place extension 32 upon boom 22, the anchor of the cylinder ofcylinder assembly 40 is detached from connection 30 and the pin assemblywhich pivotably connects aperture, 104 of boom 22 with connection 34,are disassembled. The shoe-shaped extension member 32 is thenover-fitted upon the distal end of the boom 22 with slide blockassemblies 70 positioned so as to cause slide blocks 78 to beintermediate slide plates 94 and 96. This can be done by placing slideblocks 78 along with bushings 77 intermediate guide plates 94 and 96, byplacing extension member 32, absent pin 76, plate 74 and bolt 72 uponboom 22, and thereafter inserting pin 76 into bushings 77 and securingbolts 72 within their respective threaded apertures in the plate 42 andthe box member 60. If it is desired to have extension member 32 in itsretracted position upon the boom 22, then slide blocks 78 are positionedimmediately adjacent stop plates 100and a pin assembly is insertedthrough apertures 88 and 104 of extension member 32 and boom 22,respectively. If it is desired to position extension member 32 in itsextended position upon boom 22, then slide blocks 78 are positionedadjacent their respective stop plates 98 and the pin assembly ispositioned through apertures 80 and 104 of extension member 32 and boom22, respectively. Thereafter, the cylinder end of cylinder assembly 24is anchored to anchor plates 42 of extension member 32 by means of a pinconnection through apertures 66. A pin assembly is fitted through pivotconnection 34 of pivot member 36 and through aperture 90 of extensionmember 32 to complete reattachment of dipper stick 38 to backhoeapparatus 10.

T o reposition extension member 32 from its extended to its retractedposition, the pin assembly interconnecting apertures 80 and 104 ofextension member 32 and boom 22, respectively, is removed. Boom cylinderassembly 24 is actuated to raise the boom, causing extension member 32,by the force of gravity, to move away from the distal end of boom 22until slide blocks 78 come to rest adjacent stop plates 100. Guideplates 94 and 96 are oriented parallel to top surface 102 of the distalend of boom 22, so that slide blocks 78 move parallel to surface 102.This aligned parallel movement automatically causes aperture 88 ofextension member 32 to align with aperture 104 of boom 22, so that thepin assembly may be inserted therethrough when extension member 32 hasreached its full retracted position. The retracted position is thepreferred position When backhoe 10 and tractor 12 are being transportedfrom one job site to another, since interference with power lines andthe like is avoided.

To reposition extension member 32 from its retracted position to itsextended position, the pin assembly is removed from apertures 88 and104. Backhoe bucket 54 is placed upon the ground and dipper cylinderassembly 40 is actuated, causing extension member 32 to move forwardlyalong boom 22 until slide blocks 78 are adjacent stop plates 98. At thispoint, aperture 80 of extension member 32 will be aligned with aperture104 of boom 22, and a pin assembly may be inserted therethroughfollowing which backhoe apparatus 10 is again ready for trenchingservice.

Extension member 32 may be repositioned (by one man) from the retractedposition to the extended position (or vice versa) with respect to theillustrated embodiment, in less than five minutes.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is, therefore, to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore to be embraced therein.

What is claimed and desired to be secured by United States LettersPatent is:

1. In a tractor mounted backhoe apparatus having a boom and a dipperstick pivotably connectable with said boom, the improvement comprisingextension means solely interconnecting said boom and said dipper stick,said extension means over-fitting the distal end of said boom and beingpivotably attached to said dipper stick, said extension means havingmeans movably attached to said boom in at least one location and meansfixedly locatable in at least one of a plurality of selectablelocations.

2. In a tractor mounted backhoe having a boom normally carrying a dipperstick pivotally mounted at one end thereof and having an actuatingcylinder anchored to said boom and a piston rod pivoted to said dipperstick, the improvements of a boom extension element of hollow box-likeconfiguration telescopically slidable over said boom, interengagingslide means on said boom, said extension accommodating relativetelescopic boom-extension movement, an anchor bracket on said extensionto which said cylinder is attachable, said extension having a pair ofspaced apertures selectively registrable with said one end of said boom,and means selectively insertable through said extension apertures andinto said one end of said boom to secure said extension and said boominto assembly in a pair of relatively telescoped positions.

3. In a tractor mounted backhoe having a boom normally carrying a dipperstick pivotally mounted at one end thereof and having an actuatingcylinder anchored to said boom and a piston rod pivoted to said dipperstick, the improvements of a one-piece, integral boom extension elementof hollow box-like configuration telescopically slidable over said boomhaving slidable attachment means interengaging slide means on oppositesides of said boom, said extension accommodating relative telescopicboomextension movement, an anchor bracket on said extension to whichsaid cylinder is attachable, said extension having a pair of spacedapertures selectively registrable with said one end of said boom, and apin assembly selectively insertable through either of said extensionapertures and into said one end of said boom to secure said extensionand said boom into assembly in either of a pair of relatively telescopedpositions.

4. In a tractor mounted, hydraulically controlled trenching apparatushaving a vertically hinged tractor-support, a boom horizontallyjournaled on said support and having a journal member at the free endthereof, a dipper stick assembly normally pivotably secured to saidjournal member of said boom, a bucket pivotally connected to said dipperstick, and a hydraulic cylinder and rod assembly for pivoting saiddipper stick assembly with respect to said journal member of said boomnormally pivotably secured at one end of the cylinder thereof to saidboom;

the improvements of boom length extension rneans comprising:

a boom extension member attachable to said boom and having a pluralityof portions selectively registrable with said journal member of saidboom,

means limiting the motion of said boom extension member with respect tosaid boom member to linear sliding movement to accommodate registrationof one of said registratable portions with said boom journal member,

means statically fixing said boom extension member on said boom memberwhen one of said boom extension member portions registers with boomjournal member,

means pivotally securing said boom extension member to said dipper stickassembly,

and means pivotally securing said boom extension member to said one endof said cylinder.

5. Boom length extension means, adapted to be fitted over the end of aboom journalable with a dipper stick assembly of a hydraulicallyactuated tractor mounted backhoe, cooperating with a hydraulic cylinderand rod assembly normally journalably connected on said boom andoperable to pivot said dipper stick assembly, comprising:

a member open at one end and for over-fitting said boom end and carryingmeans for journalably connecting said over-fitting means to said dipperstick assembly,

means selectively movable for attaching said over-fitting member on theboom;

fastening means for selectively orienting the over-fitting member in anyone of several fixed positions with respectto said boom end,

and means pivotably mounted on said over-fitting member journalablyconnected to said hydraulic cylinder and rod assembly.

6. On a tractor mounted, hydraulically controlled trenching apparatuscomprising:

a vertically hinged trenching support,

a boom horizontally journaled on said support and having a journalmember,

a dipper stick assembly journalable upon said journal member of saidboom,

a hydraulic cylinder and rod assembly for rotating said dipper stickassembly with respect to said journal member of said boom,

and a bucket pivotably connected to said dipper stick,

the method of extending boom length comprising:

overlaying said boom in a translatable telescopic fashion a rigid memberjournable upon said journal member of said boom at a plurality ofcorresponding journal members on said rigid member;

journaling said dipper stick member upon said rigid member;

and providing a pivot point for said hydraulic cylinder and rod assemblyon said rigid member for a pivotable mounting therewith.

References Cited by the Examiner UNITED STATES PATENTS 1,650,255 11/1927Bannister 2l4-134 2,575,564 1l/195l Rinkel 214- 2,784,855 3/1957 Acker214-138 2,984,372 5/1961 Ferwerda 2l4-l38 HUGO O. SCHULZ, PrimaryExaminer.

2. IN A TRACTOR MOUNTED BACKHOE HAVING A BOOM NORMALLY CARRYING A DIPPERSTICK PIVOTALLY MOUNTED AT ONE END THEREOF AND HAVING AN ACTUATINGCYLINDER ANCHORED TO SAID BOOM AND A PISTON ROD PIVOTED TO SAID DIPPERSTICK, THE IMPROVEMENTS OF A BOOM EXTENSION ELEMENT OF HOLLOW BOX-LIKECONFIGURATION TELESCOPICALLY SLIDABLE OVER SAID BOOM, INTERENGAGINGSLIDE MEANS ON SAID BOOM, SAID EXTENSION ACCOMMODATING RELATIVETELESCOPIC BOOM-EXTENSION MOVEMENT, AN ANCHOR BRACKET ON SAID EXTENSIONTO WHICH SAID CYLINDER IS ATTACHABLE, SAID EXTENSION HAVING A PAIR OFSPACED APERTURES SELECTIVELY REGISTRABLE WITH SAID ONE END OF SAID BOOM,AND MEANS SELECTIVELY INSERTABLE THROUGH